Mt. Williamson- wet and loose avalanches

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AVALANCHE OBSERVATION
Bairs Creek Mt. Williamson
Submission Info
Sunday, February 12, 2017 - 1:00pm
Red Flags: 
Recent avalanche activity
Avalanche Type: 
Wet
Slope: 
35degrees
Trigger type: 
Natural
Crown Height: 
2 ft
Aspect: 
Northwest
Weak Layer: 
Old Snow
Avalanche Width: 
150ft.
Terrain: 
Below Treeline
Elevation: 
9 000ft.
Bed Surface: 
Old Snow
Avalanche Length: 
800ft.
Number of similar avalanches: 
3
More detailed information about the avalanche: 

Several wet slides that probably went naturally on Friday/Saturday primarily on NW and N facing slopes.  The starting zone were between 9000 and 9500 feet for the three wet sides we observed and each ran about 600-1000 feet with some debris blocks up to 6 feet in diameter.  Lots of broken trees and branches in the runout zones from a larger avalanche earlier in the season.  The snow pack at 8500 feet consisted of about 2 inches of light low density snow on top of an 1inch rain crust (Rain crust was present until about 10,000 feet) and then heavy wet saturated snow below for several feet below that.   Several Small loose snow slides present at about 12,000 feet on SE facing 35-45 degree slopes.  New snow (around 1:12 density) of 25-30 cm above 10,000 feet made for some awesome skiing.  Compression test at 12,000 feet on a 35 degree ENE slope failed at CT13 at a depth of about 20cm on a in storm layer of stellar crystals. 

Avalanche Photos: 
Blowing Snow: 
Yes
Cloud Cover: 
Clear
Air temperature: 
Below Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Northeast
Accumulation rate: 
None
More detailed information about the weather: 

Clear beautiful day, with light winds in the drainage and moderate 20-30mph winds on the ridge above 13000 feet.

36° 39' 23.4288" N, 118° 17' 53.8512" W

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